Sen. Ron Wyden led a group of Congress members in asking the U.S. Commerce Department to crackdown on Chinese solar manufacturers.

In its preliminary ruling issued in May, the Commerce Department called for tariffs on solar panels manufactured in China with Chinese materials on the grounds that subsidies provided by the Chinese government resulted in an unfair trade advantage.

Wyden, along with Oregon's other Democratic Sen. Jeff Merkley, Rep. Suzanne Bonamici, D-Ore., Rep. Earl Blumenauer, D-Ore. and four other lawmakers, said some Chinese manufacturers were getting around the tariffs by outsourcing one step of the production process to another country.